Jacked up the car today and jet washed the underneath to within an inch  of it's life!! Ran it up for nearly an hour, let it get red hot and no  leaks visible.
Need to have a look at the thermostat cos for some reason the fan comes  on but doesn't go off, the bottom rad hose goes cold but the top rad  hose stays red hot and the temp gauge sits at 100.
Thinking the thermostat might be stuck, tempted to run without it as  it's a cold opening stat. 85 or something so potentially it's always  open anyway. Thoughts??